1,253 research outputs found
Star formation and ISM morphology in tidally induced spiral structures
Tidal encounters are believed to be one of the key drivers of galactic spiral
structure in the Universe. Such spirals are expected to produce different
morphological and kinematic features compared to density wave and dynamic
spiral arms. In this work we present high resolution simulations of a tidal
encounter of a small mass companion with a disc galaxy. Included are the
effects of gas cooling and heating, star formation and stellar feedback. The
structure of the perturbed disc differs greatly from the isolated galaxy,
showing clear spiral features that act as sites of new star formation, and
displaying interarm spurs. The two arms of the galaxy, the bridge and tail,
appear to behave differently; with different star formation histories and
structure. Specific attention is focused on offsets between gas and stellar
spiral features which can be directly compared to observations. We find some
offsets do exist between different media, with gaseous arms appearing mostly on
the convex side of the stellar arms, though the exact locations appear highly
time dependent. These results further highlight the differences between tidal
spirals and other theories of arm structure.Comment: 17 pages, 19 colour figures, accepted for publication in MNRA
Validity of the Bottle Buoyancy Model for Body Fat Determination
International Journal of Exercise Science 10(1): 87-96, 2017. We investigated a modification of the bottle buoyancy (BB) method in comparison to single frequency, bioelectric impedance analysis (BIA) as a valid noninvasive method of percent body fat (%BF) determination. Twenty-eight participants (15 men, 13 women), in counterbalanced-order, completed the BB, BIA, and computerized hydrostatic densitometry (HD) methods. We elected to modify the BB method using a 12.15 L container with participants hugging the container in an upright position. Consistency measures of intraclass correlation coefficient (ICC), typical error (TE), coefficient of variation (CV) and total error of measurement (TEM) are reported. Our modification of the BB resulted in less “bobbing” than described in the previous method, and took ~5 to 15 min per participant to complete. Group values (%BF) did not differ (p \u3e 0.05) for BB (20.7 ± 6.6), BIA (21.0 ± 9.7), and HD (20.2 ± 7.2). Strong measurement agreement was observed between BB and HD (ICC: 0.95, TE: 1.80 %BF, CV: 10.7%, TEM: 1.77 %BF). Agreement between BIA and HD (ICC: 0.85, TE: 3.35 %BF, CV: 19.6%, TEM: 3.29 %BF) was lower than BB. Our modification of the BB method resulted in similar measurement consistency with the originating method. The BB method appears to represent a valid surrogate measure of %BF, superior to that observed with BIA
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Life in the slip lane: the effect of molecular level friction on algal adhesion
The settlement and adhesion of Navicula perminuta and Ulva linza to methyl-terminated alkanethiol self-assembled monolayers (SAMs) of increasing chain length has been investigated. Organisms were allowed to settle onto the monolayers and were subsequently exposed to hydrodynamic shear stress in order to determine their adhesion strength. Results show that as the SAM structure changes from amorphous to crystalline (C14), there is a marked change in the adhesion of N. perminuta and U. linza. Given that the SAMs in the series all exhibit similar contact angle behaviour and surface energy, it is hypothesized that the lubricity of the surface plays a role in determining the surface adhesion
Agouti C57BL/6N embryonic stem cells for mouse genetic resources.
We report the characterization of a highly germline competent C57BL/6N mouse embryonic stem cell line, JM8. To simplify breeding schemes, the dominant agouti coat color gene was restored in JM8 cells by targeted repair of the C57BL/6 nonagouti mutation. These cells provide a robust foundation for large-scale mouse knockout programs that aim to provide a public resource of targeted mutations in the C57BL/6 genetic background
Archaeosperma arnoldii-A Cupulate Seed from the Upper Devonian of North America
139-154http://deepblue.lib.umich.edu/bitstream/2027.42/48427/2/ID275.pd
Association Between Maternal Diabetes in Utero and Age at Offspring's Diagnosis of Type 2 Diabetes
OBJECTIVE—The purpose of this study was to examine age of diabetes diagnosis in youth who have a parent with diabetes by diabetes type and whether the parent's diabetes was diagnosed before or after the youth's birth
A Novel Genome-Wide Association Study Approach Using Genotyping by Exome Sequencing Leads to the Identification of a Primary Open Angle Glaucoma Associated Inversion Disrupting ADAMTS17
Closed breeding populations in the dog in conjunction with advances in gene mapping and sequencing techniques facilitate mapping of autosomal recessive diseases and identification of novel disease-causing variants, often using unorthodox experimental designs. In our investigation we demonstrate successful mapping of the locus for primary open angle glaucoma in the Petit Basset Griffon Vendéen dog breed with 12 cases and 12 controls, using a novel genotyping by exome sequencing approach. The resulting genome-wide association signal was followed up by genome sequencing of an individual case, leading to the identification of an inversion with a breakpoint disrupting the ADAMTS17 gene. Genotyping of additional controls and expression analysis provide strong evidence that the inversion is disease causing. Evidence of cryptic splicing resulting in novel exon transcription as a consequence of the inversion in ADAMTS17 is identified through RNAseq experiments. This investigation demonstrates how a novel genotyping by exome sequencing approach can be used to map an autosomal recessive disorder in the dog, with the use of genome sequencing to facilitate identification of a disease-associated variant
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